Black Widow (Latrodectus spp.) Care Sheet
Black Widows of the genus Latrodectus are among the world’s most recognisable spiders and are occasionally maintained by experienced keepers within the specialist arachnid hobby.
The genus contains numerous species distributed across warm and temperate regions worldwide. Familiar examples include the Southern Black Widow (Latrodectus mactans), Western Black Widow (Latrodectus hesperus), Northern Black Widow (Latrodectus variolus) and Brown Widow (Latrodectus geometricus).
Despite their reputation, widow spiders are not animals that actively seek confrontation with people. However, their venom is medically significant, and captive husbandry must be designed around preventing accidental contact and escape.
Widows construct irregular three-dimensional cobwebs rather than conventional circular orb webs. An established female may spend much of her time suspended within this web, waiting for prey to become entangled.
Their relatively small size and simple environmental requirements can misleadingly make them appear easy to keep. In reality, their medical significance, escape potential and ability to produce large numbers of tiny spiderlings mean that they are appropriate only for keepers prepared to use strict hands-off husbandry.
Successful keeping requires secure escape-resistant housing, abundant web anchor points, appropriate ventilation, suitable temperature and hydration, individually housed specimens, captive-bred prey and absolutely no routine handling.
Quick Facts
Scientific name: Latrodectus spp.
Common names: Black Widow, Widow Spider; individual species have additional common names
Order: Araneae
Family: Theridiidae
Distribution: Worldwide, depending upon species
Lifestyle: Web-dwelling sit-and-wait predator
Activity: Frequently nocturnal
Diet: Carnivorous
Temperature: Approximately 20–27°C for many commonly maintained species
Humidity: Species dependent; generally moderate with good ventilation
Housing: Individual
Web type: Irregular three-dimensional cobweb
Handling: Not recommended
Experience level: Advanced
Venom: Medically significant
Major requirements: Extremely secure containment, web anchor points, careful maintenance and hands-off husbandry
Genus-Level Care
Latrodectus contains numerous species occupying different climates.
This care sheet therefore provides:
general captive-husbandry principles for the genus.
Exact temperature, humidity, seasonal requirements and adult size should be researched for the particular species being maintained.
Commonly Encountered Species
Species that may be encountered in specialist captive collections include:
- Latrodectus mactans
- Latrodectus hesperus
- Latrodectus variolus
- Latrodectus geometricus
- Latrodectus tredecimguttatus
- Latrodectus menavodi
- Other Latrodectus species
Availability varies substantially between countries.
Correct Identification
Do not assume every dark spider with a red marking is:
a Black Widow.
Likewise, not every Latrodectus species is entirely black.
Correct scientific identification is important for:
- Husbandry
- Legal considerations
- Medical information
- Breeding records
Natural Distribution
Members of Latrodectus occur across:
- North America
- South America
- Europe
- Africa
- Asia
- Australia
- Numerous islands
Different species occupy very different geographical regions.
Natural Habitat
Widow spiders can inhabit:
- Dry scrub
- Grassland
- Woodland edges
- Rock crevices
- Hollow logs
- Animal burrows
- Outbuildings
- Sheds
- Garages
- Human structures
They typically select protected locations where a permanent web can be constructed.
Appearance
Adult females are usually considerably larger and more robust than males.
Depending upon species, females may display:
- Glossy black colouration
- Brown colouration
- Red abdominal markings
- Orange markings
- Pale geometric patterns
Hourglass Marking
Several well-known widow species possess a red or orange:
hourglass-shaped marking
on the underside of the abdomen.
However, markings vary according to:
- Species
- Sex
- Age
- Individual
The hourglass should not be treated as a universal identification feature for every Latrodectus.
Juvenile Colouration
Juvenile widows can look dramatically different from mature females.
Young spiders may display:
- White markings
- Orange markings
- Red markings
- Stripes
- Spots
These patterns may change significantly during growth.
Sexual Dimorphism
Sexual dimorphism is pronounced.
Adult males are typically:
- Much smaller
- More slender
- Longer-legged relative to body size
- Less heavily built
than mature females.
Female Size
Adult female body size varies by species.
Many commonly encountered widows have body lengths around:
8–15 mm, excluding the legs.
Male Size
Males are considerably smaller and may appear surprisingly delicate beside adult females.
Behaviour
An established female is generally:
web dwelling and relatively sedentary.
Once a suitable web has been constructed, she may spend much of her time within it.
Web
Widow spiders belong to the family Theridiidae.
They construct:
irregular three-dimensional cobwebs.
Web Structure
The web may appear chaotic compared with an orb-weaver’s symmetrical web.
However, it is a highly effective prey-capture structure.
Strong Silk
Widow silk can be surprisingly strong.
Keepers may notice significant resistance when old webbing is moved with forceps.
Prey Capture
When prey contacts the web, the spider detects vibrations through the silk.
It may then:
- Approach the struggling prey.
- Throw or wrap silk around it.
- Immobilise it further.
- Bite the prey.
- Feed once it has been subdued.
Housing
A secure terrestrial or semi-arboreal enclosure can work well.
The most important considerations are:
- Security
- Web-building space
- Anchor points
- Safe maintenance access
Enclosure Size
For many adult females, an enclosure approximately:
15 × 15 × 20 cm
or somewhat larger provides adequate space.
Larger species or elaborate display setups may benefit from additional room.
Enclosure Orientation
Moderate height is useful because widow spiders often suspend themselves within:
three-dimensional webs.
Secure Closure
The enclosure must have a:
reliable secure closure.
Do not rely on a lid that can easily be:
- Knocked loose
- Lifted accidentally
- Opened by a child
- Disturbed by another pet
Door Gaps
Inspect all:
- Door edges
- Ventilation holes
- Cable openings
- Hinges
- Lid gaps
carefully.
Remember that males and juveniles can pass through considerably smaller openings than adult females.
Ventilation
Provide good ventilation appropriate to the species.
Stagnant conditions should be avoided.
Cross Ventilation
Cross ventilation is preferable where practical.
It allows moisture to dissipate and reduces persistent condensation.
Web Anchor Points
The enclosure should contain abundant structures onto which silk can be attached.
Suitable materials include:
- Cork bark
- Dry twigs
- Artificial foliage
- Small branches
- Secure plastic structures
Furnishing Arrangement
Create a network of:
vertical, horizontal and diagonal attachment points.
The spider will decide how to connect them.
Do Not Overdecorate
The enclosure does not need to be packed completely full.
Maintenance still needs to be possible without placing hands close to the spider.
Substrate
Suitable substrate can include:
- Coco fibre
- Organic topsoil
- Soil mixtures
- Paper towel in simple setups
Widows do not require deep burrowing substrate.
Substrate Depth
Approximately:
2–5 cm
is generally sufficient.
Retreat
Provide at least one sheltered location such as:
- Cork bark
- Hollow decoration
- Dark crevice
The spider may incorporate this into its web.
Temperature
Temperature requirements vary between species.
For many species commonly encountered in captivity, approximately:
20–27°C
provides a useful general range.
Species Differences
A Mediterranean species and a tropical African species should not automatically receive identical seasonal conditions.
Research the:
exact species and geographical origin.
Heating
Many widows can be maintained successfully at normal warm household temperatures.
If additional heat is required, use:
gentle thermostatically controlled external heating.
Excessive Heat
Avoid uncontrolled high temperatures.
Small spider enclosures can overheat rapidly.
Direct Sunlight
Never place the enclosure in direct sunlight.
Humidity
Humidity requirements vary according to species.
The better general approach is to provide:
- Appropriate ventilation
- Access to water
- A moisture gradient where appropriate
- Periodic light hydration
rather than attempting to maintain an arbitrary humidity percentage.
Dry-Climate Species
Species originating from relatively arid environments should not be kept on:
permanently saturated substrate.
More Humid Species
Species from warmer, more humid environments may benefit from somewhat more frequent hydration.
Ventilation remains important.
Water
Adult spiders should have reliable access to hydration.
Water Dish
A small shallow water dish may be provided where the enclosure layout permits safe servicing.
Position it:
away from the spider’s primary retreat whenever possible.
Web Droplets
Occasional droplets on part of the enclosure or web structure may also provide drinking opportunities.
Avoid soaking the entire web.
Misting
If misting is appropriate for the species, apply it:
lightly and locally.
Do not directly blast the spider with water.
Lighting
Specialised lighting is unnecessary.
Provide a normal:
day/night cycle.
UVB
Dedicated UVB lighting is not required.
Feeding
Widow spiders are:
carnivorous predators.
Suitable Prey
Appropriate captive-bred prey can include:
- Crickets
- Cockroach nymphs
- Flies
- Small locusts
- Other appropriately sized feeder insects
Prey Size
Prey should be appropriately sized for the spider.
There is no need to offer extremely large prey.
Feeding Frequency
Healthy adults can generally be offered suitable prey approximately:
once every 7–14 days.
Adjust according to:
- Species
- Body condition
- Temperature
- Prey size
- Reproductive status
Feeding Through the Web
Prey can be introduced directly into an area of established web.
The resulting vibration frequently triggers a feeding response.
Feeding Response
A widow may move surprisingly quickly once prey becomes entangled.
Do not interpret its sedentary lifestyle as an inability to move rapidly.
Remove Uneaten Prey
Remove uneaten prey using:
long forceps.
Avoid reaching into the enclosure.
Wild-Caught Feeders
Avoid wild-caught insects.
They may introduce:
- Pesticides
- Parasites
- Pathogens
- Other contaminants
Use reliable captive-bred feeders.
Fasting
Adult widows can sometimes go considerable periods without feeding.
Do not continuously introduce prey simply because the spider refuses a meal.
Overfeeding
An excessively enlarged abdomen may increase vulnerability to:
physical injury.
Maintain sensible body condition.
Moulting
Juvenile widows grow through repeated:
moults.
Pre-Moult
Before moulting, the spider may:
- Refuse food
- Become less active
- Remain in a protected part of the web
Remove Dangerous Prey
If moulting is suspected, remove potentially dangerous live prey.
During Moulting
Do not:
- Handle the spider
- Destroy its web
- Introduce prey
- Disturb the enclosure unnecessarily
Freshly Moulted Spider
After moulting, the new exoskeleton and fangs require time to:
harden.
Feeding After Moulting
Wait until the spider appears fully hardened and has resumed normal behaviour before feeding.
Exuvia
The discarded exoskeleton is known as the:
exuvia.
It can be removed when accessible without excessive disturbance.
Handling
Routine handling is:
not recommended.
There is no husbandry requirement to place a widow spider on bare skin.
Medically Significant Venom
Latrodectus venom can cause:
latrodectism
following significant human envenomation.
Latrodectism
Possible effects can include:
- Significant pain
- Muscle cramping
- Abdominal or back pain
- Sweating
- Nausea
- Restlessness
- Autonomic symptoms
Severity varies considerably.
Avoid Sensationalism
Widow spiders deserve serious respect, but risk should not be exaggerated.
Bites are not automatically fatal.
Modern medical management means severe outcomes are uncommon in many regions.
The correct response is:
prevent bites rather than sensationalise them.
Higher-Risk Individuals
Any suspected bite should be treated seriously, particularly when involving:
- Children
- Elderly people
- Medically vulnerable individuals
Local medical advice should be sought promptly.
Bite Prevention
The most effective bite prevention is:
no direct contact.
Never Test Temperament
Do not deliberately:
- Touch
- Prod
- Pick up
- Restrain
a widow spider to demonstrate that it is “docile.”
Defensive Behaviour
Widows generally prefer retreat or defensive web behaviour over biting when escape is possible.
However, a spider may bite if:
- Trapped against skin
- Crushed
- Restrained
- Protecting itself or an egg sac
Maintenance Tools
Keep appropriate equipment available, including:
- Long forceps
- Secure catch cup
- Soft guiding tool
- Secondary containment tub
Hands Outside
Routine enclosure maintenance should be designed so that:
hands remain outside whenever practical.
Rehousing
Rehousing requires careful planning.
Prepare everything:
before opening the occupied enclosure.
Secondary Containment
A sensible method is to conduct the transfer inside:
a larger secure empty container.
This provides another barrier if the spider leaves either primary enclosure unexpectedly.
Transfer Area
Do not rehouse over:
- Carpet
- Clutter
- Furniture
- Open drains
- Open doors or windows
Catch Cup
Use a secure catch cup for relocation.
Never attempt to catch a widow:
with bare hands.
Individual Housing
Adult widow spiders should normally be housed:
individually.
Cannibalism
Widow spiders are capable of:
cannibalism.
The famous association between widows and sexual cannibalism does not mean every female inevitably consumes every male, but the possibility must be considered during breeding.
Sexing
Mature males and females are dramatically different.
Adult Females
Females are typically:
- Larger
- More robust
- Larger through the abdomen
- Longer lived
Adult Males
Males are generally:
- Much smaller
- More slender
- More mobile after maturity
They possess enlarged reproductive pedipalps.
Mature Male Wandering
Once mature, males may spend more time:
searching for females.
This makes enclosure security particularly important.
Breeding
Breeding Latrodectus should only be attempted by experienced keepers who are prepared to manage:
large numbers of tiny potentially medically significant offspring.
Preparing the Female
Before pairing, the female should be:
- Mature
- Healthy
- Well established
- Appropriately fed
Introducing the Male
The male is generally introduced into the female’s established enclosure or web system under controlled conditions.
Courtship
The male uses:
- Web vibrations
- Movement
- Silk manipulation
during courtship.
Cannibalism Risk
The female may attack the male.
A keeper should never assume pairing is safe simply because courtship has begun.
After Pairing
The male should not automatically be left permanently with the female.
Egg Sacs
A successfully mated female may produce:
multiple egg sacs.
Sperm Storage
Female widow spiders may store sperm after mating.
Consequently, a single successful mating can potentially result in:
multiple fertile egg sacs.
Egg-Sac Appearance
Egg-sac appearance varies by species.
Some are relatively smooth.
Others may possess distinctive external structures.
Brown Widow Egg Sac
The Brown Widow (Latrodectus geometricus) is particularly well known for producing:
spiky or tufted-looking egg sacs.
This can assist identification when combined with other characteristics.
Egg-Sac Guarding
Females may become more defensive while associated with egg sacs.
Disturbance should be minimised.
Spiderlings
A single egg sac may contain:
numerous spiderlings.
Multiple sacs can therefore result in a very large number of offspring.
Before Breeding
Before pairing adults, prepare:
- Secure juvenile containers
- Extremely fine ventilation
- Tiny feeder cultures
- Appropriate space
- A responsible placement plan
Spiderling Escape Risk
Widow spiderlings are:
extremely small.
They can escape through openings that easily contain an adult.
Ventilation for Spiderlings
Ventilation must be:
exceptionally fine and secure.
Spiderling Food
Suitable foods may include:
- Flightless fruit flies
- Very small flies
- Other appropriately tiny captive-bred prey
Cannibalism Among Spiderlings
Cannibalism may occur as spiderlings develop.
Individual housing becomes the safest long-term approach.
Separating Spiderlings
Separating large numbers of medically significant spiderlings is a substantial undertaking.
This is one of the main reasons inexperienced keepers should:
not breed widow spiders casually.
Accidental Egg Sacs
Wild-caught adult females may already have mated before entering captivity.
A female obtained from the wild may therefore produce:
fertile egg sacs without ever being paired by the keeper.
Captive-Bred Animals
Captive-bred specimens are preferable whenever available.
They provide better information regarding:
- Species
- Age
- Origin
- Previous husbandry
Labelling
Every enclosure should be clearly labelled with:
- Scientific name
- Appropriate venom warning
- No-handling warning
Shared Households
Anyone with access to the enclosure should understand:
- The enclosure must not be opened
- The spider should never be handled
- Escape prevention is essential
Children
A widow enclosure should be completely inaccessible to:
children.
Other Pets
Keep the enclosure somewhere:
- Cats cannot knock it over
- Dogs cannot reach it
- Other pets cannot disturb it
Secure Room
For medically significant species, a dedicated secure invertebrate room or locked area provides an additional level of protection.
Enclosure Placement
Choose a location that is:
- Stable
- Quiet
- Away from direct sunlight
- Away from vibration
- Away from heavy household traffic
- Inaccessible to unauthorised people
Escape Planning
Before acquiring a widow spider, decide how an escape would be managed.
Have:
- Catch cups
- Long tools
- Suitable containers
available before they are needed.
Cleaning
Widow enclosures generally require relatively little invasive cleaning.
Routine maintenance consists primarily of:
- Removing prey remains
- Maintaining hydration
- Removing accessible waste
- Checking enclosure security
Preserve the Web
Do not repeatedly destroy established webbing simply for cosmetic reasons.
The web is the spider’s:
primary living structure.
Major Cleaning
Complete cleaning or rehousing should only be performed when genuinely necessary.
Household Insecticides
Spiders are extremely sensitive to pesticides.
Keep the enclosure away from:
- Fly spray
- Flea treatments
- Ant killer
- Cockroach treatments
- Garden pesticides
Aerosols
Avoid spraying near the enclosure:
- Air freshener
- Perfume
- Cleaning products
- Deodorising aerosols
Health
Potential husbandry-related problems include:
- Dehydration
- Excessive moisture
- Poor ventilation
- Overheating
- Failed moults
- Injury
- Chemical contamination
Common Husbandry Mistakes
Common mistakes include:
- Underestimating the species because it is small
- Attempting routine handling
- Using an insecure enclosure
- Providing inadequate web anchor points
- Destroying established webbing unnecessarily
- Keeping inappropriate species in permanently saturated conditions
- Allowing prolonged dehydration
- Leaving dangerous prey during moulting
- Overfeeding
- Using wild-caught feeder insects
- Rehousing without secondary containment
- Housing adults together
- Allowing children access
- Failing to label the enclosure
- Underestimating the escape ability of males and spiderlings
- Breeding without preparing for potentially large numbers of offspring
Are Black Widows Suitable for Beginners?
No.
Their environmental requirements can be relatively simple.
That does not make them beginner spiders.
The principal challenge is:
risk management and secure containment.
Appropriate Keeper
A prospective keeper should already understand:
- Basic spider husbandry
- Secure enclosure design
- Hands-off maintenance
- Catch-cup transfers
- Moulting
- Web-dwelling spider behaviour
- Medically significant species protocols
They should be considered:
advanced specialist spiders.
Availability in the Hobby
Latrodectus species are maintained by specialist arachnid enthusiasts and can occasionally be obtained as captive-bred specimens.
Availability varies considerably according to:
- Species
- Country
- Legislation
- Breeder activity
They are therefore relevant to a broad exotic-pet care library despite not being conventional mainstream pets.
Why Keepers Maintain Them
Responsible specialist keepers may be interested in widows because of their:
- Web-building behaviour
- Striking appearance
- Feeding behaviour
- Sexual dimorphism
- Reproductive biology
- Scientific interest
They should be maintained for observation rather than physical interaction.
Educational Value
Widow spiders provide opportunities to observe:
- Cobweb construction
- Prey wrapping
- Venomous predation
- Sexual dimorphism
- Courtship
- Egg-sac production
- Spiderling development
- Spider silk behaviour
Responsible Sourcing
Captive-bred animals should be preferred.
Before purchasing, ask:
- What is the exact species?
- Is the identification reliable?
- Is it captive bred?
- What developmental stage is it?
- What prey is it eating?
- Has an adult female previously been paired?
The final question can be particularly important because females may retain sperm.
Wild-Caught Females
A wild-caught mature female may unexpectedly produce fertile egg sacs.
This can transform ownership of:
one spider into responsibility for many spiderlings.
Captive-bred animals with known history are therefore preferable.
Legal Considerations
Legislation concerning medically significant spiders varies substantially between jurisdictions.
Depending upon location, Latrodectus possession may be:
- Unrestricted
- Regulated
- Permit controlled
- Prohibited
Always verify current local requirements.
Dealer Availability Does Not Guarantee Legality
The fact that a specimen is advertised by:
- A breeder
- An online seller
- A pet shop
- An expo vendor
does not automatically mean possession is lawful where the purchaser lives.
Transport
Secure containment is especially important during transport.
Use:
multiple secure barriers
where appropriate.
Never Release Captive Widows
Never release captive:
- Adults
- Juveniles
- Spiderlings
- Egg sacs
into the environment.
This applies even where another Latrodectus species occurs naturally.
Responsible Ownership
Before obtaining a Latrodectus, ensure you can provide:
- Secure escape-resistant housing
- Suitable web-building structure
- Appropriate ventilation
- Correct species-specific temperature
- Appropriate hydration
- Captive-bred feeder insects
- Individual housing
- Long maintenance tools
- Secure catch containers
- Controlled rehousing procedures
- Safe placement away from children and pets
- Long-term specialist care
Summary
Black Widows and related widow spiders of the genus Latrodectus are fascinating web-dwelling spiders maintained by some specialist arachnid keepers.
They construct irregular three-dimensional cobwebs and spend much of their lives suspended within these silk structures waiting for prey.
Adult females are considerably larger and more robust than males and, depending upon species, may display the familiar combination of glossy dark colouration and red or orange markings.
For many species, a secure enclosure around 15 × 15 × 20 cm or larger provides useful captive space when furnished with numerous web anchor points.
A broad temperature range around 20–27°C is appropriate for many commonly maintained species, but exact requirements must be adjusted according to species and geographical origin.
Adults can generally be offered appropriately sized captive-bred prey approximately every 7–14 days, adjusted according to body condition and temperature.
Established webbing should be preserved whenever possible because it forms the spider’s primary living and hunting structure.
The greatest husbandry consideration is safety.
Latrodectus venom is medically significant and can cause latrodectism. Routine handling is therefore inappropriate.
Secure containment, long maintenance tools, catch cups and controlled transfer procedures should be considered normal husbandry equipment.
Breeding requires particularly careful planning because females can produce multiple egg sacs and large numbers of extremely small spiderlings.
With appropriate experience, secure housing and responsible hands-off management, Latrodectus can be fascinating specialist home-kept arachnids.
They are not appropriate beginner spiders and should never be treated as handling pets.
IMPORTANT INFORMATION
Latrodectus species are medically significant spiders intended only for experienced, responsible keepers.
This care sheet covers the genus generally. Temperature, humidity, seasonal requirements and other husbandry details vary between species, so always research the exact species being maintained.
Routine handling is not recommended.
Keep specimens individually in secure, clearly labelled enclosures inaccessible to children, pets and unauthorised household members.
Use long tools for maintenance and secure catch-container procedures for transfers.
Provide abundant anchor points and preserve established webbing whenever possible.
Never place an enclosure in direct sunlight.
Remove potentially dangerous feeder insects when moulting is suspected and allow freshly moulted spiders to harden before feeding.
Adult females may store sperm and produce multiple fertile egg sacs. Wild-caught females may therefore produce offspring unexpectedly.
Do not breed Latrodectus unless you are prepared to securely house and feed potentially large numbers of tiny spiderlings.
Do not exaggerate or minimise venom risk. Widow bites can produce medically important systemic symptoms, but a bite should not automatically be described as fatal. Bite prevention through secure hands-off husbandry is the appropriate approach.
Always verify local legislation concerning possession, breeding, sale, transport, import and export before obtaining medically significant arachnids.
Never release captive adults, juveniles, spiderlings or egg sacs into the environment.
Information correct at the date of publication.
reptilecommunity.com | Revised: August 2026